/* Copyright 2000-2008 MySQL AB, 2008-2009 Sun Microsystems, Inc.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; version 2 of the License.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */

/* For use with thr_lock:s */

#ifndef _thr_lock_h
#define _thr_lock_h
#ifdef	__cplusplus
extern "C" {
#endif

#include <my_pthread.h>
#include <my_list.h>

    struct st_thr_lock;
    extern ulong locks_immediate, locks_waited;

    /*
      Important: if a new lock type is added, a matching lock description
                 must be added to sql_test.cc's lock_descriptions array.
     */
    enum thr_lock_type {
        TL_IGNORE = -1,
        TL_UNLOCK, /* UNLOCK ANY LOCK */
        /*
          Parser only! At open_tables() becomes TL_READ or
          TL_READ_NO_INSERT depending on the binary log format
          (SBR/RBR) and on the table category (log table).
          Used for tables that are read by statements which
          modify tables.
         */
        TL_READ_DEFAULT,
        TL_READ, /* Read lock */
        TL_READ_WITH_SHARED_LOCKS,
        /* High prior. than TL_WRITE. Allow concurrent insert */
        TL_READ_HIGH_PRIORITY,
        /* READ, Don't allow concurrent insert */
        TL_READ_NO_INSERT,
        /* 
       Write lock, but allow other threads to read / write.
       Used by BDB tables in MySQL to mark that someone is
       reading/writing to the table.
         */
        TL_WRITE_ALLOW_WRITE,
        /*
          WRITE lock used by concurrent insert. Will allow
          READ, if one could use concurrent insert on table.
         */
        TL_WRITE_CONCURRENT_INSERT,
        /* Write used by INSERT DELAYED.  Allows READ locks */
        TL_WRITE_DELAYED,
        /* 
          parser only! Late bound low_priority flag. 
          At open_tables() becomes thd->update_lock_default.
         */
        TL_WRITE_DEFAULT,
        /* WRITE lock that has lower priority than TL_READ */
        TL_WRITE_LOW_PRIORITY,
        /* Normal WRITE lock */
        TL_WRITE,
        /* Abort new lock request with an error */
        TL_WRITE_ONLY
    };

    enum enum_thr_lock_result {
        THR_LOCK_SUCCESS = 0, THR_LOCK_ABORTED = 1,
        THR_LOCK_WAIT_TIMEOUT = 2, THR_LOCK_DEADLOCK = 3
    };


    extern ulong max_write_lock_count;
    extern my_bool thr_lock_inited;
    extern enum thr_lock_type thr_upgraded_concurrent_insert_lock;

    /*
      A description of the thread which owns the lock. The address
      of an instance of this structure is used to uniquely identify the thread.
     */

    typedef struct st_thr_lock_info {
        pthread_t thread;
        my_thread_id thread_id;
    } THR_LOCK_INFO;

    typedef struct st_thr_lock_data {
        THR_LOCK_INFO *owner;
        struct st_thr_lock_data *next, **prev;
        struct st_thr_lock *lock;
        mysql_cond_t *cond;
        enum thr_lock_type type;
        void *status_param; /* Param to status functions */
        void *debug_print_param;
        struct PSI_table *m_psi;
    } THR_LOCK_DATA;

    struct st_lock_list {
        THR_LOCK_DATA *data, **last;
    };

    typedef struct st_thr_lock {
        LIST list;
        mysql_mutex_t mutex;
        struct st_lock_list read_wait;
        struct st_lock_list read;
        struct st_lock_list write_wait;
        struct st_lock_list write;
        /* write_lock_count is incremented for write locks and reset on read locks */
        ulong write_lock_count;
        uint read_no_write_count;
        void (*get_status)(void*, int); /* When one gets a lock */
        void (*copy_status)(void*, void*);
        void (*update_status)(void*); /* Before release of write */
        void (*restore_status)(void*); /* Before release of read */
        my_bool(*check_status)(void *);
    } THR_LOCK;


    extern LIST *thr_lock_thread_list;
    extern mysql_mutex_t THR_LOCK_lock;

    my_bool init_thr_lock(void); /* Must be called once/thread */
    void thr_lock_info_init(THR_LOCK_INFO *info);
    void thr_lock_init(THR_LOCK *lock);
    void thr_lock_delete(THR_LOCK *lock);
    void thr_lock_data_init(THR_LOCK *lock, THR_LOCK_DATA *data,
            void *status_param);
    enum enum_thr_lock_result thr_lock(THR_LOCK_DATA *data,
            THR_LOCK_INFO *owner,
            enum thr_lock_type lock_type,
            ulong lock_wait_timeout);
    void thr_unlock(THR_LOCK_DATA *data);
    enum enum_thr_lock_result thr_multi_lock(THR_LOCK_DATA **data,
            uint count, THR_LOCK_INFO *owner,
            ulong lock_wait_timeout);
    void thr_multi_unlock(THR_LOCK_DATA **data, uint count);
    void
    thr_lock_merge_status(THR_LOCK_DATA **data, uint count);
    void thr_abort_locks(THR_LOCK *lock, my_bool upgrade_lock);
    my_bool thr_abort_locks_for_thread(THR_LOCK *lock, my_thread_id thread);
    void thr_print_locks(void); /* For debugging */
    my_bool thr_upgrade_write_delay_lock(THR_LOCK_DATA *data,
            enum thr_lock_type new_lock_type,
            ulong lock_wait_timeout);
    void thr_downgrade_write_lock(THR_LOCK_DATA *data,
            enum thr_lock_type new_lock_type);
    my_bool thr_reschedule_write_lock(THR_LOCK_DATA *data,
            ulong lock_wait_timeout);
    void thr_set_lock_wait_callback(void (*before_wait)(void),
            void (*after_wait)(void));
#ifdef	__cplusplus
}
#endif
#endif /* _thr_lock_h */
